Arc-lamp.



J. H. ALLEN.-

ARG LAMP.

APYLIOATION FILED m1111116, 190e.

996,392-, lPatented June 27, 1911.

v 4 2 SHEETS-SHEET 1.

LH. ALLEN.

ARG LAMP. APPLICATION FILED Mums, 1906.

Patented June 27, 1911.

2 SHEETS-911219952.

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mem'frg J .An/141my UNITED srArEs Parana" OFFICE.

JOSEPH H. ALLEN, OEGHICAGO, ILLINOIS, AsSIGNOPaIBY MESNE ASSIGNMENTS, ToGENERAL'ELEOTRIC COMPANY, A CORPORATION OE. NEW YORK.

ARC-LAMP.

`To all whom it may concern:

Be it known that I, JOSEPH II. ALLEN, citizen of the` UnitedI States,residing at Chicago, i-n the county of Cook and State of Illinois, haveinvented a certain'new and useful Improvement in Arc-Lamps, of which thefollowing is az full, clear, concise, and exact description.

My invention relates to an electric arc lamp, and has for its object toprotect the carbon-lifting magnet from abnormal currents which wouldburn out the'y coils thereof. Considerable difficulty has beenexperienced heretofore in arc lamps due to such burning out of t-he feedmagnet coils, which is often ycaused by the clutch member, after beingraised by the magnet core to lift the upper carbon and establish an arc,allowing-the upper carbon .to slip down into engagement with the lowerlcarbon, thereby'greatly decreasing the resistance of t-he circuit andpermitting an abnormally heavy current to flow through the liftingmagnet.

My invention contemplates the provision.

of a .thennostatict'rod expansible upon the 4passage of an abnormalcurrent through the lifting magnet, adapted to short circuit saidmagnet,.and permit the armature and clutch to drop into position toseparate the carbons when the lifting magnet is again energized. Ipreferably employ a thermostatic rod connected in series with the feedor lifting magnet, said rod, upon the passage of an abnormally heavycurrent in the circuit,

'expanding to close a pair of contacts conabout the liftingv trolling ashort circuit magnet, which thereupon releases its core or armature andallows the .clutch member to fall int-o position to grasp the uppercarbon and reestablish the arc when thelifting magnet is againenergized. l The contacts referred to also close at the same time ashort circuit about thethermostatic rod, and as soon 'as lthe rod Vcoolsand contracts, it separates the contacts referred'to and opens vvtheshort circuits, whereupon the lifting magnet is energized and separatesthe carbons to reestablish the arc.

f A feature of-imy'invention consists in the provision` of means`adapted to avoid any ".:possibil-itybf the thermostatic rod closingitsshort circuit in case said rod should be-` Specification of LettersPatent. Patented June 2'?, 1911, Application filed March 16, 1906.

Serial No. 306,363.

perature in the lamp. To this end I employ a thermostat independent ofthe circuit of the lamp, which permits the first thermostat to respondto an abnormally heavy current in the lamp and close the short circuit,but which prevents the said first mentioned thermostat, whenv itresponds to an abnormally high temperature closing said short circuit.

I will describe my invention more particularly by reference to theaccompanying drawings, wherein- Figure l is a front elevation of a lampequipped with a protecting device for the lift-ing magnet embodying myinvention; Fig. 2 is a longitudinal sectional view of the protectivedevice; Fig. 3 is a plan view thereof; Fig. I is a plan of t-he lamp,from view of a modified form of' protective device embodying myinvention and provided with means for prevent-ing the thermostatic rodfrom operating its contacts to short circuit the lifting magnet when thetemperature o f the lamp is abnormally raised; Fig. 5 is a sectionalview on line 5 5 of Fig. 4,; and Fig. 6 is a `simplified circuit diagramofthe lamp shown in Fig. 1. y

Similar letters of reference designate like parts throughout the severalviews;

The lifting magnet a of the arc lamp show'n in Fig.l 1 is provided .withthe usual armature or core for operating the clutch b to separate thetwo carbons of the lamp. thermostatic rod c of metal is includedserially in the circuitof the magnet a, and 1s secured at one end to apost c mounted upon an insulating base c2, the other end of said rodbeing connected to the lower end of a spring arm c3, said post andsprlng arm having suitable terminals upon-the under side of the blockc2. The rod c when expanded, due to the passage of an abornal current inits circuit, is` adapted tomove the spring arm c3 into engagementwith acontact post c4- and thereby close a short circuit about the liftingmagnet a, said contacts c3 c4 when closed also completing a shortcircuit around the rod c.

Referring to Fig. 6, the circuit of the lamp and its protective devicewill be readily apparent. rIhe normal circuit extends from the positiveterminal of the lamp by way of conductor 1 to the spring arm c3, thenceto rod c and post 0, through the lifting magnet a to the upper carbon ofthe lamp, and thence by w'ay of the lower carbon and conductor 2 to thenegative terminal of the lamp. When no current is passed through thelamp, the carbons are in contact, as shown, butl when the circuit abovereferred to is completed, the lmagnet a is energized and draws up itscore or armature, which operates the clutch Z) shown in Fig. 1, toseparate the carbons and establish an arc. Now, it for any reason theclutch should accidentally release the upper carbon while the core isattracted and allow the upper car bon to fall into engagement with thelower carbon, the arc would no longer be present and the resistance ofthe circuit greatly decreased, whereupon the abnormally heavy currentwould flow through the circuit 1, 2 and, if permitted to ilow for anylength of time would burn out the coils of the magnet a, Thethermostatic rod c, being in the circuit, is heated and expanded by thisadnormally heavy current, and moves the spring arm c3 into engagementwith the contact post c", which is connected by conductor 3 withconductor 1, between the magnet a and the upper carbon, thereby shortcircuiting the magnet a, which allows its core t0- gether with theclutch, to fall into position to lift the upper carbon when the magnet ashall again .become energized. rllhe contacts c3 c4 when closed alsoshort circuit the rod c by way of conductor, and rod c is allowed tocool. When cooled, the rod contracts and separates the contacts c3 c4,breaking the short circuit referred to and permitting current to flowthrough the magnet a, which draws up its core and separates the carbonsto reestablish the arc. The rod c isv preferably adjustably secured tothe post c', so that the distance between the contacts c3 c4 may bevaried as desired, the rod c oit course being rigidly secured to thespring arm 0,3. Such adjustment may be secured in the manner most fullyshown in Figs. 2 and 3 in which the rod c passes through or is otherwisesecured to a set screw 05, said set screw being adjustable in the postc.

1n order to prevent any possibility of an abnormally high temperature ofthe lamp caused by theheat of the arc, from heating and expanding thethermostatic rod and closing the contacts ce c4, may employ the type ofprotective device shown in Figs. 4: and 5, which is provided with meansvfor rendering the rod c ineiifectively responsive to such an abnormallyhigh temperature.

I provide a rocking lever d connected at one side d of its pivot withone end of the thermostatic rod c, the other end of said rod beingconnected with a spring member e. A

second thermostatic rod 7 is connected at ceases one end with the leverd at the other side d2 of its pivot, being insulated therefrom by asuitable bushing, and 'the other end of said rod f is connected with thespring member e. The lever (Z is provided with a suitable ter minalunderneath its supporting base, which would be connected with conductor1 in the manner of spring .arm c3 shown in Fig. 6, and the spring memberc is provided with a similar terminal connected with conductor 1 in themanner of supporting'post c of Fig. 6. An extension d4 of the lever d,which preferably lies parallel with the rods c, f, is provided with anormally-open contact d5 with which it is adapted to engage when thelever d is rocked by the expansion of the rod c, these contacts Z4 Z5corresponding to the contacts c3 c4 shown in Fig. 6.

When an abnormally heavy current passes through the rod c and the magneta, the rod c is heated and expands, rocking the lever d t0 closethecontacts Z4 d5. Since no current passes through the rod f, it will notbe expanded and will cooperate with the spring member e to permit therocking lever ci to close contacts Zt d5. In case, however, anabnormally high temperature is present in the lamp, both rods c f willbe expanded and will move the spring member c to the left without,however, affecting the lever d.

ll claim 1. In an electric arc lamp, the combination with anarc-controlling magnet, of a circuit therefor, a thermostatic rod insaid circuit adapted to respond to an abnormal current therein, arocking lever connected at one side of its ivot with one end of saidrod, a spring memer to which the other end of said rod is connected, ashort circuit about said magnet closed by said lever when rocked bytheexpansion of said rod, and a thermostatic rod connecting said lever atthe other side of its pivot with said spring member to prevent theclosure of said short circuit when the lamp temperature is abnormallyraised.

2. In an electric arc lamp, the combination with an arc-controllingmagnet, of a circuit therefor, a thermostatic rod in said circuitresponsive to an abnormal current therein, 'a rocking lever connected atone side of its pivot with one end of said rod, a spring lever to whichthe other end of said rod is connected, an extension of said arm,

a normally-open contact adapted to be en-y gaged by said arm when saidlever is rocked by the expansion of said rod, a short circuit about saidmagnetclosed by said extension and its contact, and a thermostatic rodinsulated from said lever and connecting the -same at the other'side ofits pivot with said spring member, both of said rods expanding upon anabnormal increase in the lamp temperature to prevent rocking of saidlever.

3. ln an electric arc lamp, the combination with an arc-controllingimagnet, of a tem perature of the lamp to prevent the opcircuit therefor', arocking lever adapted eratlon of said lever. -10 when operated to closea short circuit about In .Witness whereof, I hereunto subscribe saidmagnet, and a pair of thermostatic y name this 13th' day of MarchA.'D.,1906. rods, one of said rods being included in said JOSEPH H.ALLEN. circuit to respond t0 abnormal currents and Witnesses:

operate said lever, both of said rods ojoerat-v RAY. -T. ALLOWAY,

ing in response to` any abnormally high BERT. S. YORK.

